Joint-specific hand symptoms and self-reported and performance-based functional status in African Americans and Caucasians: The Johnston County Osteoarthritis Project

Objective

To assess associations between joint‐specific hand symptoms and self‐reported and performance‐based functional status.

Methods

Participants were from the population‐based Johnston County Osteoarthritis Project. Symptoms in the distal interphalangeal (DIP), proximal interphalangeal (PIP), first carpometacarpal (CMC), and metacarpophalangeal (MCP) joints were assessed on a 30‐joint diagram of both hands. Self‐reported function was assessed by Health Assessment Questionnaire (HAQ) and performance‐based function by timed repeated chair stands and 8‐foot walk time. Separate multiple logistic regression models examined associations between symptoms in specific hand joint groups, symptoms in ⩾2 hand joint groups and number of symptomatic hand joints, and functional status measures, controlling for age, race/ethnicity, sex, body mass index, radiographic knee and hip OA, knee and hip symptoms and depressive symptoms.

Results

Those with symptomatic hand joint groups were more likely than those without these complaints to report more difficulty and require longer times for performance measures. Those with 2 or more symptomatic hand joint groups were more likely to have higher HAQ scores (OR = 1.97 (1.53 to 2.53)) and require more time to complete 5 chair stands (OR = 1.98 (1.23 to 3.18)) and the 8 foot walk test (OR = 1.49 (1.12 to 1.99)).

Conclusions

Joint‐specific hand symptoms are associated with difficulty performing upper‐ or lower‐extremity tasks, independent of knee and hip OA and symptoms, suggesting that studies examining functional status in OA should not ignore symptomatic joints beyond the joint site of interest, even when functional measures appear to be specific for the joint site under study.Osteoarthritis (OA) is a common cause of pain and disability.^1,2 Pain, aching or stiffness attributed to hand OA is associated with functional limitations in activities requiring use of the hands.^3,4 Individuals with OA of both the hands and knees have higher (worse) Health Assessment Questionnaire (HAQ) scores than those with isolated hand or knee OA.⁵ Unrecognised concomitant hand symptoms could potentially confound studies using the HAQ to follow symptoms of hip or knee OA, especially since a significant number of patients with isolated hip or knee OA alone will develop hand OA over time.⁵ Despite this, investigations of the impact of upper‐ or lower‐extremity OA traditionally use questions, functional tests or even selected components of the HAQ restricted to upper‐ or lower‐extremity function.^4,6,7 We have previously reported an association between knee pain and difficulty performing not just lower‐extremity tasks but upper‐extremity tasks as well, suggesting possible concomitant upper‐extremity involvement in the participants in the Johnston County Osteoarthritis Project.⁸ In this study, we examined associations between joint‐specific hand symptoms, as surrogate measures of hand OA, and self‐reported and performance‐based measures of functional status. Additionally, we evaluated whether these associations were independent of radiographic hip and knee OA and hip and knee symptoms, and whether these associations varied by race/ethnicity, sex, and the presence of knee or hip symptoms.